Singlet oxygen quantum yields from halogenated chlorins: potential new photodynamic therapy agents

• Autor(a) principal: Pineiro, Marta
• Data de Publicação: 2001
• Outros Autores: Pereira, Mariette M., Rocha Gonsalves, A. M. d'A., Arnaut, Luis G., Formosinho, Sebastião J.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10316/5228; https://doi.org/10.1016/S1010-6030(00)00382-8
• topic: Photoacoustic calorimetry; Chlorin; Singlet oxygen; Sensitisers; Photodynamic therapy

Flash photolysis and photoacoustic calorimetry were used to measure the energy-transfer rates and singlet oxygen quantum yields originated by the triplet states of halogenated tetrakisphenylporphyrins and related chlorins in aerated toluene. The chlorins ([lambda]max[approximate]660 nm, [var epsilon][approximate]3×104 M-1 cm-1) have long-lived triplet states (>12 [mu]s) in the absence of molecular oxygen, and in its presence the singlet oxygen production quantum yields of the 2-chloro and 2,6-dichlorophenyl derivatives are 0.89±0.05 and 0.98±0.02, respectively. The high absorptivity in the red, the photostability and the efficiency of these chlorins in producing singlet oxygen suggests a ground for the development of better sensitisers for photodynamic therapy.